Sealing structure

Abstract

A sealing device exhibits a sealing function even when it is in a state in which squeeze of a seal ring is reduced and in a low-temperature condition. A sealing structure is provided with a cylinder head ( 300 ) for an engine which has an injector mounting hole ( 310 ) and is exposed to high pressure gas; an injector which is mounted in the injector mounting hole ( 310 ); and a seal ring ( 100 ) made of resin which seals an annular gap between the injector mounting hole ( 310 ) and the injector ( 200 ), wherein a step having a larger diameter on a combustion chamber side (E) where the high pressure gas is present is formed on an inner peripheral surface of the injector mounting hole ( 310 ), and the seal ring ( 100 ) is attached to a position where the seal ring is in close contact with a step surface ( 310 c ) of the step.

The invention claimed is: 
     
       1. A sealing structure comprising:
 a member which has a mounting hole and is exposed to high pressure gas; 
 a mounted component which is mounted in the mounting hole; 
 a seal ring which is formed of a single member made of resin and seals an annular gap between the mounting hole and the mounted component, wherein 
 a step having a larger diameter on a side where the high pressure gas is present is formed on an inner peripheral surface of the mounting hole, and 
 the seal ring is attached to a position where the seal ring is in direct contact with a step surface of the step; and 
 wherein the mounted component is provided with a tapered surface which increases in diameter from the side where the high pressure gas is present to an opposite side thereto, and the seal ring is compressed against the tapered surface by a pressure of the high pressure gas. 
 
     
     
       2. The sealing structure according to  claim 1 , wherein a step surface formed by deformation of an outer peripheral surface of the seal ring is in close contact with the step surface of the step formed on the inner peripheral surface of the mounting hole.